Telegraphy.



PATENTED AUG. 20, 1907.

I. KITSBB.

TBLEGRAPHY. APPLICATION TILED 133.24, 1907.

WITNESSES:

I N VEN TOR.

ISIDOR KITSEE, OF PHILADELPHIA, PENNSYLVANIA.

TE LE GRAPHY.

Specification of Letters Patent.

Patented Aug. 20, 1907.

Application filed April 24:, 1907. Serial No. 369,969.

To all whom it may concern:

Be it known that I, Isrnon Krrsnn, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Telegraphy, of which the following is a specification.

My invention relates to an improvement in telegraphy.

Its object is to enable persons versed in the art to transmit simultaneously two messages from opposite directions over the line of transmission.

This system, on account of its simplicity and ease of handling, lends itself readily to railroad work, wherein a series of stations are connected to one line. The system is also applicable to general telegraph work, and if only two terminals of the stations are inserted, the system may also be employed in submarine cable work.

The drawing represents in diagram a telegraphic circuit embodying my invention.

1 is the line of transmission; 2 and 3 are the batteries inserted in the line at the terminals, both batteries consisting of equal cells and connected to the line in opposition as to each other. The line is grounded at 4.

The drawing illustrates the line to contain the three stations A, B and C. One station is a duplicate of the others and similar devices are similarly designated. Each station comprises the electro-magnet 5 which may be a simple sounder or any other electro-magnetic translating device.

In all respects this device may be similar to the device now in use, with the exception that the coil thereof, here designated by the numeral 6, is provided at different points with outside contacts, here designated by the numeral 7. In proximity to these contacts is the switch 8 connected with the interposition of transmitting means to the ground 4. These transmitting means are illustrated in the drawing as to consist of the lever 9 and the stationary point 10 of a usual transmitting key, but it is obvious that instead of the manual transmitter, any of the well known transmitters may be substituted.

The operation of this arrangement is as follows: As long as the line is idle, that is, none of the stations are working, the energy from 2 being opposed by the energy from 3, no current will flow over the line, but as soon as the line is grounded on any other point, then the energy from both the batteries 2 and 3 will flow each over parts of the line and will return by the additional ground. It is supposed that the operator at station A desires to transmit a message. If he would connect the line directly to the ground either before or after the device 5, then either one or the other of the currents from 2 or 3 will flow through the device and the same will answer to the flow of this current, but as it is desired that the home device should remain neutral to the home transmission, I have provided means so that the influence of the current from the far off station should be neutralized by the influence of the current from the home station, and this means consists therein that the grounding of the line is not made directly, but is made through part of the coil of the receiving device 5; and as the ratio of neutralization varies, I have provided means whereby a greater or lesser part of the coil 6 of the receiving device 5 may be connected to the ground and thereby the home current be made to flow through a greater or lesser number of convolutions of said coils. When the operator at A transmits a message and, therefore, connects one or the other of the contacts 7 through the interposition of the key to the ground, a path is established for the current of the far off station, which travels or flows through the whole coil of the instrument of the far-off station through the whole line to the station which is transmitting this message. Here the current flows only through that part of the coil which is not grounded and hence to energize the core to a certain polarity. But as the current from the home station travels through that part of the coil which is grounded and as the flow of this current is in opposition to the flow of the current from the far-off station, it is obvious that if the effects of these two currents are equalized, the home instrument will not answer.

It is understood that the number of cells has to vary in accordance with the length of the line and the desired effect; so also has the type of the receiver to vary in accordance with requirements; so also the number of contacts coming from the coil of said receiver.

It is advised, that the person in charge of the station should, before the commencement of a message or better at the beginning of every working day, balance his coil, so as to know with what particular contact the switch should be connected to give the best results.

As long as only the operator of one station, say the station A, as illustrated in the drawing, transmits a message, a current will flow from the battery 3 over the line in the direction of the unfeathered arrow, will flow through one part, here shown as the upper part, of the coil of device 5 of said station and at the same time a current will flow from the battery 2 through the other part of said coil, here shown as the lower part, and, as said above, the magnetizing effect of both coils will be in opposition as to each other and will, therefore,

neutralize each other; but as soon as simultaneously To persons versed in the art, it will be apparent that with such arrangement, the duplexing of the line can easily be carried out commercially and the cumbersome arrangements of artificial lines and alike devices are eliminated.

I stated above that this system can also be practiced with submarine cables and, indeed, in submarine cables, the simultaneous transmission of message in 0pposite directions, if each of the two stations is equipped with an arrangement as described and illustrated, is easily accomplished.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is 1. In combination, a telegraphic line, terminal batteries for said line, said batteries in opposition as to each other, terminal and intermediate stations for said line, each station provided with an electro magnetic device inserted in series in said line, and means for each station to ground a greater or lesser part of the coil of said electromagnetic device.

2. In a system of telegraphy wherein two sources of current are connected to the line in opposition as to each other, means to make the home instrument immune to the home transmission, said means comprising adjustable means to connect part of the coil of the home instrument to the return.

3. ,A system of telegraphy comprising a line of transmission, a source of current for each terminal thereof, a series of stations for said line, a receiving device for each station, and means to connect part of the coil of the receiving device to the return, in accordance with the characters to be transmitted.

4. Means to duplex a telegraphic line, said means comprising; an electro-magnetic device inserted in said line, two sources of current in opposition as to each other connected to said line, and adjustable means to connect part of the coil of said receiving device to the return.

5. In duplex telegl'aphy, a line of transmission, two or more stations therefor, an electro-magnetic device inserted in the line for each station, and means dependent on the operation of the transmitting means to cause two currents to simultaneously flow each to one part of one common coil, and means to vary the proportion of the coil for the flow of each current in a manner, so as to neutralizetheir magnetizing effect.

In testimony whereof I atfix my signature in presence of two witnesses.

ISIDOR KITSEE.

Witnesses:

EDITH R. SrILLnY, MARY 0. SMITH. 

